This investigation seeks to determine if oral endotoxins (lipopolysaccharides, LPS) exhibit the teratogenic and embryolethal properties that have been demonstrated for the enteric endotoxins. Endotoxins from enteric organisms have been shown to induce congential malformations, spontaneous abortions, decreased fetal weight and increased fetal mortality in various animal models. The primary objective of this proposal is to compare endotoxins purified from Bacteroides gingivalis and Escherichia coli for teratogenic and embryolethal potential in the pregnant Golden Hamster model. The experimental protocol will involve a single intravenous bolus of enteric endotoxin or oral endotoxin at eight days of gestation during the peak of organogenesis, using timed-pregnancy hamsters. One day prior to partuition (day 15), animals will be sacrificed; resorption sites and implantation sites will be counted. Fetuses will be weighed and inspected for viability and gross malformations. Pregnancy outcome responses will be obtained using various dosages of purified Bacteroides gingivalis LPS and Escherichia coli LPS. The long-term objective of this research is to assess the potential for an andotoxemia of oral origin as a possible etiology in birth complications in humans. It is well established that even rather innocuous self-inflicted dental manipulations such as toothbrushing and chewing can result in transient recurrent bacteremias of dental origin. Thus, gram-negative periodontal organisms may serve as a reservoir for inducing low-level endotoxemias. The effects of chronic exposure to low levels of LPS on pregnancy outcome is unknown. Accordingly, experiments will be performed to obtain dosage-response data using oral and enteric LPS delivered continuously during pregnancy by daily injection or via subcutaneously implanted osmotic mini-pumps.